source: main/trunk/gli/src/org/greenstone/gatherer/file/FileSystemModel.java@ 34255

package org.greenstone.gatherer.file;

import java.io.File;
import java.util.*;
import java.util.regex.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import org.greenstone.gatherer.DebugStream;
import org.greenstone.gatherer.Gatherer;
import org.greenstone.gatherer.gui.tree.DragTree;


public class FileSystemModel
    extends DefaultTreeModel 
    implements TreeExpansionListener, TreeWillExpandListener
{
    private DragTree tree = null;
    private FileFilter current_filter = null;
    private FileFilter[] filters = null;
    /** The filters in place for any file system model. */
    private FileFilter[] default_filters = { new FileFilter("\\..*", true), new FileFilter("metadata\\.xml", true) };

    public FileSystemModel(FileNode root) {
    super(root);
    root.setModel(this);
    root.refresh();
    }

    public int getChildCount(Object parent) {
    return ((TreeNode)parent).getChildCount();
    }

    public FileFilter[] getFilters() {
    if(filters == null) {
        if(current_filter != null) {
        filters = new FileFilter[default_filters.length + 1];
        filters[default_filters.length] = current_filter;
        }
        else {
        filters = new FileFilter[default_filters.length];
        }
        System.arraycopy(default_filters, 0, filters, 0, default_filters.length);
    }
    return filters;
    }
     
    /** Retrieve the node denoted by the given tree path. Note that this isn't equivelent to saying path.lastPathComponent, as the references within the path may be stale. */
    public FileNode getNode(TreePath path) {
    FileNode last = (FileNode)path.getLastPathComponent();
    DebugStream.println("Last Path Component = " + last);
    return last;
    /*
    ///atherer.println("**** getNode(" + path + ") ****");
    FileNode current = (FileNode)root;
    // Special case for the root node. Check the first path component is the root node.
    FileNode first_node = (FileNode)path.getPathComponent(0);
    if(current.equals(first_node)) {
        DebugStream.println("First path component matches root node.");
        // For each path with this tree path
        for(int i = 1; current != null && i < path.getPathCount(); i++) {
        // Retrieve the stale path
        Object stale_object = path.getPathComponent(i);
        FileNode stale_node = null;
        if(stale_object instanceof FileNode) {
            stale_node = (FileNode) stale_object;
        }
        DebugStream.print("Searching for '" + stale_object + "': ");
        // Locate the fresh node by searching current's children. Remember to ensure that current is mapped.
        boolean found = false;

        // First we search through the mapped children
        for(int j = 0; !found && j < current.getChildCount(); j++) {
            FileNode child_node = (FileNode) current.getChildAt(j);
            DebugStream.print(child_node + " ");
            if((stale_node != null && stale_node.equals(child_node)) || stale_object.toString().equals(child_node.toString())) {
            found = true;
            current = child_node;
            DebugStream.println("Found!");
            }
            child_node = null;
        }
        // Failing that we search through all the children, including filtered files
        for(int j = 0; !found && j < current.size(); j++) {
            FileNode child_node = (FileNode) current.getChildAtUnfiltered(j);
            DebugStream.print(child_node + " ");
            if((stale_node != null && stale_node.equals(child_node)) || stale_object.toString().equals(child_node.toString())) {
            found = true;
            current = child_node;
            DebugStream.println("Found!");
            }
            child_node = null;
        }
        // If no match is found, then set current to null and exit.
        if(!found) {
            current = null;
            DebugStream.println("Not Found!");
        }
        else {
            DebugStream.println("Returning node: " + new TreePath(current.getPath()));
        }
        // Repeat as necessary
        }
    }
    return current;
    */
    }

    public void insertNodeInto(MutableTreeNode newChild, MutableTreeNode parent, int index) {
    ///ystem.err.println("insertNodeInto(" + newChild + ", " + parent + ", " + index + ")");
    super.insertNodeInto(newChild, parent, index);
    }


    public void refresh(TreePath path)
    {
    // Can only refresh if the model is currently being displayed in a tree
    if (tree == null) {
        return;
    }

    // If no path is set, take the path to the root node (ie. update the whole tree)
    if (path == null) {
        // System.err.println("\nFileSystemModel.refresh(entire tree).");
        path = new TreePath(((FileNode) root).getPath());

        // Make sure the root node is expanded
        tree.expandPath(path);
    }
    // else {
    //     System.err.println("\nFileSystemModel.refresh(" + path + ").");
    // }

    // Record all the expanded paths under this node
    Enumeration old_expanded_paths_enumeration = tree.getExpandedDescendants(path);
    if (old_expanded_paths_enumeration == null) {
        return;
    }

    // Map and unmap the node to refresh its contents
    FileNode node = (FileNode) path.getLastPathComponent();
    node.refresh();

    // Fire the appropriate event
    nodeStructureChanged(node);

    // Sort the old expanded paths by length, smallest first
    ArrayList old_expanded_paths_list = Collections.list(old_expanded_paths_enumeration);
    Collections.sort(old_expanded_paths_list, new TreePathComparator());

    // Restore each of the expanded paths
    for (int i = 0; i < old_expanded_paths_list.size(); i++) {
        TreePath old_expanded_path = (TreePath) old_expanded_paths_list.get(i);
        // System.err.println("Expanded path: " + old_expanded_path);

        // Build up the new path in the tree
        TreePath current_path = new TreePath(path.getPath());
        FileNode current_node = node;

        // Traverse the tree to find the node to expand (or find it no longer exists)
        while (!current_path.toString().equals(old_expanded_path.toString())) {
        // System.err.println("Current path: " + current_path);

        FileNode old_expanded_node =
            (FileNode) old_expanded_path.getPathComponent(current_path.getPathCount());
        // System.err.println("Looking for: " + old_expanded_node);

        // Find the child node that matches the next element in the path
        boolean found = false;
        for (int j = 0; j < current_node.getChildCount(); j++) {
            FileNode child_node = (FileNode) current_node.getChildAt(j);
            // System.err.println("Child node: " + child_node);
            if (child_node.equals(old_expanded_node)) {
            // System.err.println("Found!");
            current_path = current_path.pathByAddingChild(child_node);
            current_node = child_node;
            found = true;
            break;
            }
        }

        // The node was not found, so we cannot expand this path
        if (!found) {
            // System.err.println("Not found...");
            break;
        }
        }

        // If we have built up the correct path, expand it
        if (current_path.toString().equals(old_expanded_path.toString())) {
        tree.expandPath(current_path);
        }
    }
    }


    // The file tree can be filtered, so check that the node to be removed is actually part of the model
    public void removeNodeFromParent(MutableTreeNode node)
    {
    TreeNode parent_node = ((FileNode) node).getParent();
    if (parent_node != null && parent_node.getIndex((FileNode) node) != -1) {
        super.removeNodeFromParent(node);
    }
    }


    private class TreePathComparator
    implements Comparator {

    public int compare(Object o1, Object o2)
    {
        return (((TreePath) o1).getPathCount() - ((TreePath) o2).getPathCount());
    }
    }


    public void setFilter(String pattern) {
    if(pattern != null) {
        current_filter = new FileFilter(pattern, false);
    }
    else {
        current_filter = null;
    }
    filters = null;
    }

    public void setTree(DragTree tree) {
    this.tree = tree;
    }

    public String toString() {
    if(tree != null) {
        return tree.toString();
    }
    return "FileSystemModel";
    }

    /** Called whenever an item in the tree has been collapsed. */
    public void treeCollapsed(TreeExpansionEvent event) {
    // Deallocate the affected nodes children. Don't need to do this in a swing worker, as the nodes children are currently not visable.
    TreePath path = event.getPath();
    FileNode node = (FileNode) path.getLastPathComponent();
    node.unmap();
    // Fire the appropriate event.
    nodeStructureChanged(node);
    }

    /** Called whenever an item in the tree has been expanded. */
    public void treeExpanded(TreeExpansionEvent event) {
    }

    /** Invoked whenever a node in the tree is about to be collapsed. */
    public void treeWillCollapse(TreeExpansionEvent event) 
    throws ExpandVetoException {
    // Veto the event if the user is attempting to collapse the root node (regardless of whether it is visible).
    TreePath path = event.getPath();
    if(path.getPathCount() == 1) {
        throw new ExpandVetoException(event, "Cannot collapse root node!");
    }
    }


    /** Invoked whenever a node in the tree is about to be expanded. */
    public void treeWillExpand(TreeExpansionEvent event) 
    throws ExpandVetoException
    {
    // Set the wait cursor
    Gatherer.g_man.wait(true);

    // Allocate the children (don't need a swing worker since the node's children are currently not visible)
    TreePath path = event.getPath();
    FileNode node = (FileNode) path.getLastPathComponent();
    node.refresh();
    nodeStructureChanged(node);

    // Restore the cursor
    Gatherer.g_man.wait(false);
    }
}